So-called "intelligent" gear-change programs for electro-hydraulically controlled automatic transmissions of passenger cars are known.
Such an intelligent gear-change program has been described for example, in DE-OS 39 22 051 wherein by "intelligent" is understood that the driver of a vehicle not have to actuate any selector button for adjusting a certain gear-change range, as for example, for sport driving or economic driving, since on the basis of input variables an electronic gear control device infers the driver's behavior and thus the type of driver. As input signals serve, for example, the signal of a throttle valve, the speed of an internal combustion engine and the longitudinal and transverse acceleration determined from the wheel speeds. According to the prior art, a driving activity or a driver type is determined from input variables. Based on the driver type a corresponding gear-change characteristic is selected from a plurality of gear-change characteristics. Thus, for example, a gear-change characteristic having low gear-change points is selected for a steady driver type and for a sport driver type is selected a gear-change characteristic having high gear-change points.
Since the driver's driving behavior can be different in different driving situations, an otherwise sporting driver who nevertheless prefers slower start-ups, would in this driving situation find inconvenient a general classification of his driving behavior as sporting. The gear-change program must therefore be capable of flexibly reacting to different driving situations.
German Patent 41 36 613 has disclosed a process relative to a start-up in which the throttle valve change is observed during the start-up. Said throttle valve change is compared with a preset throttle valve range, said comparison leading to the selection of an adequate category of driving style.
But this process known from the prior art has the disadvantage that the evaluation of the start-up with reference to the throttle valve change, which does not reproduce the actual behavior of a vehicle, is subject to errors.
Therefore, this invention is based on the problem of providing a process which improves the above cited prior art with regard to a slight defectiveness in the evaluation of a start-up in comparison with the actual behavior of the vehicle.